Shortness of breath during pregnancy

Shortness of breath is a common and normal part of pregnancy. It affects nearly 60 percent of pregnant women. Find out why.

Why do pregnant women experience shortness of breath?

At the start of pregnancy

During the first trimester, you may experience shortness of breath due to changes in your respiratory system, which must supply oxygen to the placenta and the fetus.

Toward the end of pregnancy

The pressure caused by your uterus expanding against your diaphragm decreases your lung capacity, which can also cause breathlessness. The diaphragm, which is more stretched, then loses some of its elasticity, resulting in shortness of breath. The expanding uterus also causes the contents of the abdomen (for example, the stomach) to move against the diaphragm, making it harder for the lungs to stretch.

If this is your first pregnancy, you may experience a decrease in shortness of breath in the last few weeks before giving birth. At this stage, the baby settles into the mother’s pelvis, thus reducing pressure on the diaphragm. For subsequent pregnancies, as the fetus often drops during labour, this sensation is less common.

How can I reduce the discomfort of shortness of breath?

A few strategies can help you feel less out of breath:

• Watch your posture and keep your back straight.
• Elevate the head of your bed slightly or use an extra pillow to sleep in a semi-seated position.
• Repeat the following exercise until you can breathe more easily:
  - Stand with your feet on the floor or lie on your back with your legs bent.
  - Inhale slowly while raising and stretching your arms over your head. This movement stretches the rib cage.
  - Exhale slowly while bringing your arms back down to your sides.
• Avoid places where people smoke whenever possible because secondhand smoke can be harmful to your health and that of your baby.
• Stay active, whether through physical activity or prenatal yoga, for example, unless you have a medical contraindication.

What to watch out for

Severe shortness of breath during physical exertion or while at rest may also be related to physiological anemia of pregnancy (when blood volume increases faster than red blood cell production). Consult your doctor if your shortness of breath is accompanied by fatigue, weakness, or dizziness.

Scientific review: Roxanne Piché, nursing adviser, Maternal Fetal Medicine Clinic, CHU Sainte-Justine Research and copywriting: The Naître et grandir team Updated: August 2019